Neighbours heard glass smashing and car tyres spinning as a getaway driver fled, leaving his alleged accomplice fighting with the owner of a van they are thought to have been trying to break into.
During an "altercation" with the van owner, the remaining offender lost consciousness. He was taken to hospital in a critical condition.
But locals say they don't believe their neighbour - a "good guy" who never caused trouble - would intentionally have hurt anyone.
Police were called just after 4am on Sunday to a report of an attempted break-in of a van at the back of a property on Te Atatu Rd in West Auckland.
The van's owner had interrupted the break-in, police said.
A family living next door say they woke at 3.52am to glass smashing and men "fighting and screaming". They heard tyres screeching and saw a white station wagon hooning toward Te Atatu with its boot still open.
One family member called the police, while a man continued screaming for several minutes before going silent.
The injured man was taken to Auckland City Hospital, with police initially saying he had a critical head injury. But they now say it's not clear why the man lost consciousness. The second alleged thief has not been found.
The owner of the van was taken to Waitākere Hospital in a moderate condition, but has since been discharged.
The neighbours were shocked at the possibility their "really nice" middle-aged neighbour could have hurt anyone.
"I could hear one of the thieves who must have been screaming every 5-10 seconds," the neighbour said. The man sounded "drunk" and "obviously in a lot of pain".
"Our neighbour - he was more worried about the thief. We could hear the whole conversation from our house, it was like he was looking after the thief until the cops came. He's really nice - he said, 'Are you OK? Come on mate'."
When St John ambulance officers arrived and took the alleged offender away on a stretcher the man was not moving. He appeared to be an older man with a pot belly, the neighbours said.
They estimated the van's owner was in his mid-30s or 40s. He was a tradie who was often doing maintenance on the house, where he lived with his sister.
The family had been interviewed by police.
A woman who lived behind the house was stuck on her property all morning yesterday as the shared driveway was cordoned off and treated as a crime scene.
Police in boiler suits were examining the scene, taking photos of the white van and the driveway.
She had heard nothing, having gone to bed about 2am when her security guard brother got home. Around 4am or 5am police knocked at her door to ask if she'd heard anything and told her not to leave the house.
She was concerned for her "very decent" neighbour's wellbeing, and expressed doubt that the man would have attacked anyone.
"He is a very good guy. There must be more to that story because he's a very nice guy," she said.
"He's not like a very muscular [guy] who would go getting into fights."
If she had heard the altercation she would have sent her brother to help, she said. She was trying to reassure her 8-year-old daughter, who was now too scared to leave the house and had locked all the doors.
Since the police station down the road had moved she had noticed an increase in crime in the area.
"Three years ago it was never like this - it was so safe I could leave my door open."
A police investigator at the scene declined to comment as it could jeopardise the investigation.
Police want to speak with witnesses and anyone who saw anything suspicious. They also want to speak to the person who drove away from the scene.
No one else was being sought in relation to the incident and there was not believed to be any risk to the public.
Anyone with information was advised to contact the Waitemata Crime Squad on 09 839 0697 or Crimestoppers anonymously on 0800 555 111.